Hi Bill,

With our Chevy big block powered Tost winches at Lasham,
you cannot slow down by pulling back - if anything
it has the opposite effect and risks breaking the weak
link. Easing forwards also makes you go faster, so
the only way to slow down is to signal to the winch
driver by wagging the tail with the rudder.

However we tried out a Skylaunch 2 winch for one day
last week with a very similar engine and gearbox, but
with a sophisticated throttle stop system. With that
I could control the speed from the glider, at least
in a K21, by about 5 knots either side of the mean
speed, which was ideal anyway. Maybe this is because
you are being supplied with just the right amount of
power. Unfortunately I didn't get a chance to try this
out with a lighter glider.

Derek Copeland

At 18:36 16 December 2007, Bill Daniels wrote:
Actually guys, you CAN and SHOULD control airspeed
on some winches. There
are few winches that have enough power to prevent a
large, heavy glider from
pulling down the drum RPM. Maybe you guys have one
- maybe not.

If you are a little too fast, pitch up, load the winch
a little and wait to
see what the airspeed does. In most cases, it will
ease back down to the
desired airspeed. If you are a bit slow, lower the
nose which unloads the
winch a bit and wait for the effect. Once you get
the hang of it, it works
sweet.

Many pilots think this won't work becasue they haven't
tried it. Give it a
try and get back to us.

Bill Daniels


'Andreas Maurer' wrote in message
.. .
On Wed, 12 Dec 2007 22:33:24 +0000, Martin Gregorie
wrote:

Speaking for myself, I watched the video and saw a
succession of
launches with right wing low. As wing low launching
is something that,
on my field, would earn you a talk with the duty instructor,
I was
unhappy with the description of this being a 'best
practices' event and
said so.

I agree, Martin.
I've never seen such a series of really critical winch
launches
before. With all due respect - a very serious ground-loop
accident is
going to happen rather sooner than later.


Comment on launch speed. The rules we use a
- after lift off, maintain a shallow climb until the
ASI passes 50 kts
with steady acceleration.
- then and only then rotate slowly. The ideal is to
complete rotation
not less than 5 seconds after lift off.
- we have a high torque, high inertia, fluid clutch
winch. The pilot
cannot and should not attempt to control its speed
except by
signalling the winch driver.
- if you're above Vwinch when the launch starts to
flatten toward the
top (i.e. when the angle is below 35 degrees or
so), release.
- if the speed drops toward 50 kts, lower the nose
to maintain at least
50 kts and monitor the speed.
- if the speed picks up, resume the climb.
- if the nose approaches level and the speed doesn't
rise, release.

The same rules apply for us. Works like a charm.



Bye
Andreas